Improvement in attachments to carpenters  squares



1. HYMAN.-

Attachment tb Carpenters Squares;

No. 136,653, Patent edMarchH,1873.

AM PHOTO-LITHUGRAFHIC c0. N)((0$BORIIE.'9 moms) UNITED STATES PATENT OFFICE.

JOHN HYMAN, OF BELVIDERE, NEW JERSEY, ASSIGNOR TO HIMSELF AND I SAMUEL SHERRERD, OF SAME PLACE.

IMPROVEMENT IN ATTACHMENTS TO CARPENTERS. SQUARES.

Specification forming part of Letters Patent No. 136,653, dated March 11, 1873.

To all whom it may concern:

Be it known that I, JOHN HYMAN, of Belvidere, New Jersey, have invented a new and useful Improvement in Carpenters Squares, of which the following is a specification:

My invention provides an instrument that can be used as an ordinary square, a tri-square, center-square, miter-square, or bevel-square, and is constructed and operates as hereinafter more fully set forth.

In the accompanying drawing, which is a view in perspective of my improvement, a rule having a longitudinal slot, a, and suitably graduated on its edges, is shown as connected to a carpenter-square, B, by an adjusting-arm, O, in which a longitudinal slot, 0, is cut. The adjusting-arm G is connected to the square near its angle by a screw, D, passing through the square and through the slot 0, and made fast therein by a wing-nut, d; and the rule A and arm 0 are connected by a screw, E, passing'through the slots at and c, and tightened as required by a nut. The arm 0 can thus swing-about the screw D as a center, and the rule A can similarly swing about the screw E, the office of the rule A being to form the hypotenuse of a right angled triangle, of which the square forms the two sides.

7 The rule is, by the above-described construction, provided with means for compound adjustment, by which it can be readily and quickly moved into any positionfrelatively to the sides of the square, respectively, that' may be required for laying off different angles or hevels. The screws serve to securely retain it in the required position while in use.

By adjusting the rule so that it shall extend to points at equal distances from the angle of the square on the two arms thereof, and adjusting the arm (3 so that one of its edges shall bisect the hypotenuse of the rightangled triangle thus formed, a center-square is provided; and for laying ofi' bevels it is simply necessary to set the rule to correspond with the length required for the sides, respectively.

It will be obvious that the slotted arm can be readily attached to an ordinary rule by simply drilling a hole for the insertion of the screw d.

I claim as my invention- The combination of the square, the slotted rule, and the slotted adjusting-arm, substantially as set fort-h.

In testimony whereof I have hereunto subscribed my name.

JQHN HYMAN.

Witnesses:

E. G. WARMAN, J AS. PURNELL TOADVIN. 

